package com.databasetest;

import android.content.Context;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteOpenHelper;
import android.widget.Toast;

/**
 * Created by Administrator on 2017/4/6.
 */

public class MyDatabaseHelper extends SQLiteOpenHelper{

    public  static final String CREATE_BOOK = "create table Book("+"id integer primary key autoincrement,"
            +"author text,"
            +"price real,"
            +"pages integer,"
            +"name text)";

    public static  final  String CREATE_CATEGORY = "create table Category("+"id integer primary key autoincrement,"
            +"category_name text,"
            +"category_code integer)";


    private Context mContext;



    /**
     * 构造方法  第一个参数Context,
     * 第二个参数数据库名。
     * 第三个参数Cursor,一般传入null,
     * 第四个参数当前数据库的版本号
     */

    public MyDatabaseHelper(Context context, String name, SQLiteDatabase.CursorFactory factory, int version) {
        super(context, name, factory, version);
        mContext = context;
    }

    @Override
    public void onCreate(SQLiteDatabase db) {
        db.execSQL(CREATE_BOOK);
        db.execSQL(CREATE_CATEGORY);
        Toast.makeText(mContext,"创建成功",Toast.LENGTH_SHORT).show();

    }

    /**
     * 必须继承的方法
     * @param db
     * @param oldVersion
     * @param newVersion
     */
    @Override
    public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
        //升级跟更新版本
        db.execSQL("drop table if exists Book");
        db.execSQL("drop table if exists Category");
        onCreate(db);
    }
}
